<?php

use Symfony\Component\HttpClient\AmpHttpClient;
use Symfony\Component\HttpClient\CurlHttpClient;
use Symfony\Component\HttpClient\NativeHttpClient;
use Symfony\Component\HttpClient\Exception\TransportException;
use Symfony\Component\Finder\Finder;
use Symfony\Component\Lock\Factory;
use Symfony\Component\Lock\Store\FlockStore;

ini_set('memory_limit', '3G');
ini_set('display_errors', true);
ini_set('error_reporting', -1);
ini_set('date.timezone', 'UTC');

require __DIR__ . '/vendor/autoload.php';

set_error_handler(function ($errno, $errstr, $errfile, $errline) {
    throw new \ErrorException($errstr, $errno, E_ERROR, $errfile, $errline);
});

class Mirror {
    private $client;
    private $url = 'https://repo.packagist.org';
    private $hostname = 'repo.packagist.org';

    public function sync()
    {
#        $this->client = new AmpHttpClient();
        $this->client = new CurlHttpClient();
#        $this->client = new NativeHttpClient();

        $rootResp = $this->download('/packages.json');

        //if ($rootResp->getHeaders()['content-encoding'][0] !== 'gzip') {
        //    throw new \Exception('Expected gzip encoded responses, something is off');
        //}
        $rootData = $rootResp->getContent();

        $rootJson = json_decode($rootData, true);
        if (null === $rootJson) {
            throw new \Exception('Invalid JSON received for file /packages.json: '.$rootData);
        }

        $requests = [];
        foreach ($rootJson['provider-includes'] as $listing => $opts) {
            $listing = str_replace('%hash%', $opts['sha256'], $listing);
            $listingResp = $this->download('/'.$listing);

            $listingData = $listingResp->getContent();
            if (hash('sha256', $listingData) !== $opts['sha256']) {
                throw new \Exception('Invalid hash received for file /'.$listing);
            }

            $listingJson = json_decode($listingData, true);
            if (null === $listingJson) {
                throw new \Exception('Invalid JSON received for file /'.$listing.': '.$listingData);
            }

            foreach ($listingJson['providers'] as $pkg => $opts) {
                $provPath = '/p/'.$pkg.'$'.$opts['sha256'].'.json';
                $provAltPath = '/p/'.$pkg.'.json';

                $provPathV2 = '/p2/'.$pkg.'.json';
                $provPathV2Dev = '/p2/'.$pkg.'~dev.json';

                $userData = [$provPath, $provAltPath, $opts['sha256']];
                $requests[] = ['GET', $this->url.$provPath, ['user_data' => $userData]];

                $headers = rand(0,1) === 0 ? ['If-Modified-Since' => gmdate('D, d M Y H:i:s T')] : [];
                $userData = [$provPathV2, null, null];
                $requests[] = ['GET', $this->url.$provPathV2, ['user_data' => $userData, 'headers' => $headers]];

                $headers = rand(0,1) === 0 ? ['If-Modified-Since' => gmdate('D, d M Y H:i:s T')] : [];
                $userData = [$provPathV2Dev, null, null];
                $requests[] = ['GET', $this->url.$provPathV2Dev, ['user_data' => $userData, 'headers' => $headers]];

                if (\count($requests) > 10000) { #XXX change here the max num of requests to do
                    break 2;
                }
            }

            $listingsToWrite['/'.$listing] = [$listingData, strtotime($listingResp->getHeaders()['last-modified'][0])];
        }

        $hasFailedRequests = false;
        echo count($requests), "\n";

        while ($requests && !$hasFailedRequests) {
            $responses = [];
            foreach (array_splice($requests, 0, 1000) as $i => $req) { #XXX change here the max num of requests per batch
                $responses[] = $this->client->request(...$req);
            }

            $i = 0;
            foreach ($this->client->stream($responses) as $response => $chunk) {
                try {
                    // TODO isLast here can probably be dropped after we upgrade to symfony 4.3.5 with https://github.com/symfony/symfony/pull/33643
                    if ($chunk->isFirst()/* || $chunk->isLast()*/) {
                        if ($response->getStatusCode() === 304) {
                            echo '3';
                            $response->cancel();
                            continue;
                        }

                        if ($response->getStatusCode() === 404) {
                            $userData = $response->getInfo('user_data');

                            // provider v2
                            if (null === $userData[1]) {
                                echo '4';
                                $response->cancel();
                                continue;
                            }
                        }
                    }

                    if ($chunk->isLast()) {
                        echo '.';
                        $userData = $response->getInfo('user_data');

                        if (null === $userData[1]) { // provider v2
                            $providerData = $response->getContent();
                            if (null === json_decode($providerData, true)) {
                                // abort all responses to avoid triggering any other exception then throw
                                array_map(function ($r) { $r->cancel(); }, $responses);
                                echo 'X1';
                                dump($response);
                                dump(\strlen($providerData));
                                throw new \Exception('Invalid JSON received for file '.$userData[0]);
                            }

                        } else { // provider v1
                            $providerData = $response->getContent();
                            if (null === json_decode($providerData, true)) {
                                // abort all responses to avoid triggering any other exception then throw
                                array_map(function ($r) { $r->cancel(); }, $responses);
                                echo 'X2';
                                throw new \Exception('Invalid JSON received for file '.$userData[0]);
                            }
                            if (hash('sha256', $providerData) !== $userData[2]) {
                                // abort all responses to avoid triggering any other exception then throw
                                array_map(function ($r) { $r->cancel(); }, $responses);
                                echo 'X3';
                                throw new \Exception('Invalid hash received for file '.$userData[0]);
                            }
                        }
                    }
                } catch (\Throwable $e) {
                    dump($e->getMessage());
                }
            }
        }

        if ($hasFailedRequests) {
            return false;
        }

        return true;
    }

    private function download($file)
    {
        try {
            $resp = $this->client->request('GET', $this->url.$file);
            // trigger throws if needed
            $resp->getContent();
        } catch (TransportException $e) {
            // retry once
            usleep(10000);
            $resp = $this->client->request('GET', $this->url.$file);
            // trigger throws if needed
            $resp->getContent();
        }

        if ($resp->getStatusCode() >= 300) {
            throw new \RuntimeException('Failed to fetch '.$file.' => '.$response->getStatusCode() .' '. $response->getContent());
        }

        return $resp;
    }
}

try {
    $mirror = new Mirror();
    echo ($mirror->sync() ? 'SUCCESS' : 'FAIL').PHP_EOL;
} catch (\Throwable $e) {
    echo 'Failed at '.date('Y-m-d H:i:s');
    throw $e;
}